Construction of aeroplane wings of variable relative thickness for the purpose of improving their aerodynamic qualities



Sept. 16 1924. 1,508,592

. BREGUET CONSTRUCTION OF AEROPLANE WINGS' OF VARIABLE RELATIVE THICKNESS FOR THE PURPOSE OF IMPROVING THEIR AERODYNAMIC QUALITIES Filed Nov. 5, 1922 Patented Sept. 16, 1924.

NITED STATES PATENT OFFICE.-

LOUIS BBEGUET, F PARIS, FRANCE, ASSIGNOR TO SOCIETE ANONYME ATELIERS DAVIATION IDUIS BIBJlZGUF-Ilf, OI PARIS, FRANCE.

OONSTBUCTION'OF AEBOPLAJNE WINGS OF VARIABLE RELATIVE THICKNESS FOR THE ZEURPOSE OF IMPROVING 'rnmn AERODYNAMIC QUALITIES.

Application filed November 3, 1922. Serial No. 598,909.

To all whom it may concern:

Be it known t at I, LQUIS Bnncon'r, a citizen of France, and a resident of Paris, France, have invented new and useful Improvements in the Construction of Aeroplane Wings of Variable Relative Thickness for the Purpose of Improving Their Aerodynamic Qualities, which is fully set forth in the following specification.

The improvement of the aerodynamic qualities of avions is aquestion with which all constructors are occupied.

The present invention relates to the improvement of these qualities in the case of aeroplanes provided with wings wherein the relation between width and thickness, or the relative thickness, is variable, as now prevails in ractice for the construction of win s wit out the use of guy wires.

pv to the present time all avions have been so constructed that the values of the incidence for the various elements or wing outlines in monoplanes, as well as in biplanes and multilanes, were practically constant;

.26 these inci ence values are determined by the inclination of the chord of the wing outlines according to the sense of travel, relative to the trajectory of the avion, this trajectory coincidin with the direction of the relative speed 0 the air with respect to the avion. 1

For monoplanes with thick wings and with little or no wire bracing, the preferable ractice is to make use of a form of solid aving an equal resistance to flexion in all the parts which are in the overhan position. The adoption of this form 0 solid of uniform strength will lead to the use of a relative thickness which gradually de- 4 creases towards the ends, and the wings are given a form which as observed in lan view is trapezoidal, with the small si e of the trapezoid at the end, and the various outlines or wing elements have been hitherto ivenpractically. uniform angles of incience.

The present invention relates to a form of construction of aeroplane wings wherein the relative thickness is variable, as for example the win s of monoplanes without wire bracing, an it is essentially characterized in that the incidence value for the diiferent outlines varies inversely with the relative thickness, and in such manner that the lifting power of each. element of different outlines shall be practically constant. This construction is found to considerably improve the aerodynamic qualities of these wings.

The accompanying, drawing shews by way of example in Fig. 1 a 'monoplane without wire bracing wherein the relative thickness of the sections a b c d indicated by the broken lines is;

Section 41, adjacent the main body 1/6 Section D, at about one-third distance 1/8 Section 0 at about two-thirds distance 1/10,6 Section d, near the end 1/14 it would appear that the incidence values should be:

Section D, at 1/3 distance +2 T Section 0 at 2 3 distance +4 Sectional at t e end of the wing +6 altitudes, and t e speed of rising from the ground.

What I claim is A method and form of construction of wings having a variable. relative thickness for the purpose of improving their aerodynamic qualities and particularly the improvement in the flyin shape and the mechanical efliciency, sai construction being vcharacterized in that the incidence of action 5 upon the air of the difl'erent elements or outlines of the wings, as measured by the angle made by the chord of the outlines with the direction of the relative speed of the air, varies inversely with the relative thickness of said outlines. 10

In testimony whereof I have signed this specification.

, LOUIS BREGUET. 

